Table 1

Amsterdam placental workshop group consensus on staging and grading of maternal and fetal inflammatory responses

Inflammatory response
Stage 1 EarlyAcute subchorionitis or chorionitisChorionic vasculitis or umbilical phlebitis
2 IntermediateAcute chorioamnionitisUmbilical vasculitis (one or both arteries with or without vein) or umbilical panvasculitis (all three vessels)
3 AdvancedNecrotising chorioamnionitisNecrotising funisitis or concentric umbilical perivasculitis
Grade 1 Mild–moderateNo specific terminology/not severeNo specific terminology/not severe
2 SevereAcute chorioamnionitis, subchorionic abscessesIntense chorionic/umbilical vasculitis
OtherChronic or subacute chorioamnionitisAssociated fetal thrombi
Peripheral funisitis
Acute villitis
Acute intervillositis with intervillous abscesses
Decidual plasma cells
  • Adapted from: Redline et al 92 and Khong et al. 30